Silicon-iron-phosphorus-copper alloy



Patented Oct. 8, 1935 Edward S. Cornell, Jr., Larchmont, N. Y., asaignor to American Radiator Company, New York, N. Y., a corporation of New Jersey No Drawing. Application September 6, 1934,

Serial No. 742,975

2 Claims.

My invention relates to alloys predominately of copper content having improved characteristics.

I In devising my improved copper alloy, 1 have discovered that certain properties of copper, and

5 in particular its tensile strength, weldability and ductility are improved by adding silicon. However, upon increasing the content of silicon above a certain range, the ductility of the alloy is impaired. I have further discovered that the addition of iron to copper containing silicon imparts an increase of tensile strength to a critical point, and that the further addition of iron effects a decrease in its tensile strength and also a decrease in the weldability of the resulting alloy. My discoveries have further brought to light that the; addition of phosphorus, within a'relatively limited range of proportion, serves to increase the tensile strength and'to enhance the weldability of copper alloys containing silicon and iron, while preserving its ductility.

Summarizing the results of my discoveries, the a. more preferred forms or my alloy embody the stated constituents in the following ranges of proportional content by weight; 25 Per cent Silicon 2.00 to 2.75 Iron .10 to .15 Phosphorus"..- .01 to .02 Copper the remainder Total The most preferred embodiment of my invention comprises the stated ingredients of the following proportional content by weight:

Per cent Silicon a 2.63 Iron a Phosphorus heated to approximately 1150 C. Silicon is then admixed with the copper either by adding it to the thus heated copper or by placing the silicon at the bottom of the crucible in which the copper is melted. Theiron constituent may be added to the copper-silicon admixture in the form of an alloy of equal proportion of silicon and iron. The stated admixture is then stirred, and the phosphorus added in the form of phosphorus copper alloy.

Ingots oi the resulting alloy may be had by pouring-the molten admixture into a cast iron Copper "1 "7" pendent upon the proportions of the stated conmold, the faces of which are dressed'with lard oil and black lead. It is desirable that the molten admixture be not heated above approximately 1200" C. a I The resulting billet is-susceptible to hot rolling and cold rolling.

The scleroscope hardness of the alloy averages approximately twenty-five but may be varied over a considerable range by varying the treatment of I the material in rolling and annealing. The melting range 0! the alloy varies from 1060 c. to 1040 c. V f The tensile strength oi the alloy varies from about 60,000 pounds per square inch upwardly dependent upon the variation over a range of the 15 proportions of the stated constituents.

In the commercial production of the alloy commercially pure electrolytic copper is employed-for the copper content; commercially pure ferrosilicon oi proper relative iron and' silicon proe portion is employed as the alloy added to the copper-silicon mix.

The alloy possesses most of the desirable properties of pure copper but inaddition thereto is immune to corrosion or other chemical effect when exposed to the atmosphere under the range of atmospheric temperatures, including moisture and water. The alloy is also immune to chemical action by the various mineral and organic acids and other liquids capable of corroding commercial copper.

The alloy is characterized by its distinctively pleasing golden color, its capability of a high luster obtained by burnishing and its proof against discoloration under normal exposure to the atmosphere. These characteristics render the alloy of high utility as a casing for and parts of hot water heaters andlike fields of use.

The alloy possesses ductility to a degree destituents for rolling into rods and thin sheets,

. and for drawing wire of the alloy.

The elongation of the alloy in hot rolled and annealed status is approximately in two inches, and in cold rolled and annealed status about in two inches. The alloy is readily machinable, including deep finishes.

-A distinctive characteristic 0! alloys embodying my invention is the capability oi? autogenous welding electrically, either by the use of a carbon electrode or by the use of a thin strip of my alloy serving as an electrode; yielding substantial homogenity at the butt to butt, or overlapping or other joint, and substantially wholly tree from carbonization and oxidation. 1: desired my alloy may be employed as an electrode in electric welding of copper to copper or to copper alloy in the electric welding of the same. In such and other welding processes of my alloy, the phos-. phorus content in combination with copper and silicon and iron of respectively lesser proportion,

as above indicated, function to offset any tendency toward the formation. of gas holes or pitting of the alloy.

Alloys embodying my invention find particular commercial application as highly suitable material for boilers, inclusive of hot water boilers, hot water and steam coils, condensers, evaporators, kitchen utensils, restaurant supply equipment, urns, percolators, and other articles.

in marked saving of costs of material and also in increasing the efliciency of devices formed of the alloy utilizing the reduced wall thickness in the conduction of heat energy thereby as a factorof efilciency.

From the results of the tests which I have made of embodiments of the alloys embodying my invention, optimum results are obtained by employing minimum quantities of silicon, iron and phosphorus, the content of iron being definitely less 5 than the content of silicon and the content of phosphorus being no greater than .02 of one per cent.

I claim:

1. An alloy comprising approximately 2.00% to 10 2.75% of silicon, .10% to .15% of iron, .01% to .02% of phosphorus, and the balance of copper, said alloy having a tensile strength of at least approximately 60,000 lbs. per square inch and a melting temperature of approximately 1040 degrees centigrade, said alloy further possessing useful casting qualities, superior in mechanical properties and weldability substantially free from pitting.

2. An alloy comprising approximately 2.63% 20 of silicon, .12% of iron, .01% of phosphorus and the balance of copper, said alloy having a tensile strength of at least approximately 60,000 lbs. per.

square inch and a melting temperature of'approximately 1040 degrees centigrade, said alloy further possessing useful casting qualities, superior in mechanical properties and weldability substantially free from pitting.

EDWARD S. CORNELL, JR. 

